Cancer of the breast is the most common malignancy in white females. It represents one of every seven new cancer cases diagnosed and its incidence is rising. Based on favorable changes in stage of disease at diagnosis and survival rates, breast cancer patients comprise the largest group of postoperative female cancer patients in need of physical and psychosocial rehabilitative programs. Findings from our preliminary study demonstrate that breast cancer patients most frequently are afflicted with shoulder range of motion limitations. The primary goal of this proposed research is to determine if immediate post-surgical physical therapy is effective in the prevention of limitation of shoulder range of motion. Problems caused by the lack of physical therapy programs for these and other patients are compounded by the belief held by many clinicians that early physical therapy actually increases the incidence of postoperative complications and prolongs hospitalization. In order to address these and other cancer control issues, we propose to perform a prospective, randomized blind study. Consecutive patients scheduled to receive a modified radical mastectomy from a single breast cancer surgeon at Roswell Park Memorial Institute (RPMI) will be approached for entry into the study. Patients then will be randomly assigned into intervention or non-intervention control groups. Prior to surgery, joint range of motion will be measured. Commencing the first day after surgery, the intervention group will receive twice daily physical therapy sessions. Upon discharge, the patient will be given a home exercise program and will encouraged to perform this for a minimum of 8 weeks. Dependent variables will be measured in all patients 5 days postoperatively and at 2 and 4 months.